<div class="timer-input-group">
  <div class="input-group">
    <input v-model="hour" number>
    <div class="border-line"></div>
  </div>
  <div class="timer-separator">:</div>
  <div class="input-group">
    <input v-model="minute" number value="1">
    <div class="border-line"></div>
  </div>
  <div class="timer-separator">:</div>
  <div class="input-group">
    <input v-model="second" number>
    <div class="border-line"></div>
  </div>
</div>
